I recently tried an upgrade that is useful for fixed power cords, Lloyd Walker's wipe on SST (super silver treatment) signal enhancer, which comes with supply of excellent applicators (which could do double duty as cosmetic eye makeup applicators). It also "upgrades" interconnects, making purchase of new wires less urgent, if you have a yen to better your system's performance.
I also plugged my older components, with their fixed power cords, into the top of the line Mapleshade power strip, and was pleased how this improved the overall performance throughout the entire frequency range
By the way, there is a lower priced wipe on signal enhancer, SilClear, with a description resembling that of the Lloyd Walker SST product, but without the extra supply of special applicators, on the Mapleshade Records website.